Other interesting facts
As we already discussed, computers love binary (and hexadecimal) because the computer circuits and memory are based on "on/off" (either a signal is there or not).
- Did you know that the pictures and sound on a DVD are recorded as tiny little holes / divots that can be "read" by a laser. As the DVD spins, the laser detects if there is a hole (or not) at every location. This is turned into a series of "1"s and "0"s that the computer then turns into sound and images.
Color Mixing - RGB / Additive Color
- RGB represents the colors visible on digital displays like monitors, smart phones, and tablets
- It is also called the "Additive" Color system, because it starts as black and then color light is added
- Each of the R, G, B values can be in the decimal range of 0..255 or the hexadecimal range of 00..FF
Red = FF 00 00 or (255 0 0)
Green = 00 FF 00 or (0 255 0)
Blue = 00 00 FF or (0 0 255) - In the absence of color (no light) the RGB value is 00 00 00 we have darkness or black
- However, when the RGB values are at full strength (FF FF FF) or RGB (255 255 255), we have white light
..... blinding light is seen as white - If the values for RGB are the same, then we produce a shade of gray
Ex. RGB (45 45 45) or RGB (180 180 180) or #CCCCCC or #464646 are all different shades of gray - Other colors are defined as the mix of Red, Green, and Blue light
- In web pages or HTML, there are 256 possible colors that can be represented by name
- However, our monitors are capable of showing millions of color (16 million to be exact)
- because each of the three colors RGB can have values from 0..255, there are
256 X 256 X 256 = 256^3 = 16 777 216 possible color combinations
- could also be expressed as 16^2 X 16^2 X 16^2 = 16^6 = 16 777 216 colors
- Check out this page and the color mixer to see how hexadecimal numbers are used to express colors and check out what we discussed in class: http://www.mathsisfun.com/hexadecimal-decimal-colors.html
- After you have played a bit, I want to make sure you get some of the theory... so be sure to read over things.
Homework: Color Conversion
Part 1: Convert each of the following into the other 3 systems: (RGB Decimal, Hexadecimal, Binary, and Decimal Total)
Part 1: Convert each of the following into the other 3 systems: (RGB Decimal, Hexadecimal, Binary, and Decimal Total)
- RGB (112 134 202)
- 60 0F 83
- Decimal Total: 5 779 945 (Hint: go into Hex first with the long division method)
- 11001110 00111101 00011000